The U.K. Security Service, responsible for the country’s counterterrorism efforts, plans to send out e-mail alerts to citizens warning them of changes to the “national threat level,” a measure of the risk of terrorist attacks. It will announce the start date and details of the sign-up process soon, it said Tuesday.

The U.K. government already publishes its assessment of the current terrorist threat level online, rating it as one of five levels: low (an attack is unlikely), moderate, substantial, severe (an attack is highly likely) or critical (an attack is expected imminently).